You can uninstall the Theme Designer App in the usual way for an Ecwid app as explained here: https://support.ecwid.com/hc/en-us/articles/115005872689-Guide-to-using-Ecwid-App-Market#uninstalling-an-app-0-3
Basically:
- Go to your Ecwid Control Panel → Apps → My Apps.
- Find the Theme Designer app, click on it to reveal the details:
- Open the app details
- Click Uninstall
- Confirm you want to uninstall the app and that you’ve read the warning about billing
The app is deleted from your Ecwid store.